Southern wide very low-mass stars and brown dwarfs in resolved binary and multiple systems

Abstract

The results of the Koenigstuhl survey in the Southern Hemisphere are presented. I have searched for common-proper motion companions to 173 field very low-mass stars and brown dwarfs with spectral types > M5.0V and magnitudes J <= 14.5 mag. I have measured for the first time the common-proper motion of two new wide systems containing very low-mass components, Koenigstuhl 2 AB and 3 A-BC. Together with Koenigstuhl 1 AB and 2M0126-50AB, they are among the widest systems in their respective classes (r = 450-11900 AU). Koenigstuhl 3 A-BC contains a well-known F8V star and a M8.0+L3.0V tight binary. I have determined the minimum frequency of field wide multiples (r > 100 AU) with late-type components at 5.0+/-1.8 % and the frequency of field wide late-type binaries with mass ratios q > 0.5 at 1.2+/-0.9 %. These values represent a key diagnostic of evolution history and low-mass star and brown-dwarf formation scenarios. Additionally, the proper motions of 76 field very low-mass dwarfs are measured here for the first time.

ApJ, in press

References in corpus (5)

• Are Proxima and Alpha Centauri Gravitationally Bound?
• Southern Infrared Proper Motion Survey II: A sample of low mass stars with μ> 0.1''/yr
• A New Brown Dwarf Desert? A Scarcity of Wide Ultracool Binaries
• The widest ultracool binary
• Are isolated planetary-mass objects really isolated? A brown dwarf-exoplanet system candidate in the sigma Orionis cluster

Cited by in corpus (19)

• CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
• SpeX Spectroscopy of Unresolved Very Low Mass Binaries. II. Identification of Fourteen Candidate Binaries with Late-M/Early-L and T Dwarf Components
• BANYAN. V. A Systematic All-Sky Survey for New Very Late-Type Low-Mass Stars and Brown Dwarfs in Nearby Young Moving Groups
• CARMENES input catalogue of M dwarfs II. High-resolution imaging with FastCam
• Prospecting in Ultracool Dwarfs: Measuring the Metallicities of Mid- and Late-M Dwarfs
• Wide, Cool and Ultracool Companions to Nearby Stars from Pan-STARRS1
• The AstraLux Multiplicity Survey: Extension to Late M-dwarfs
• Contamination by field late-M, L and T dwarfs in deep surveys
• Discovery of a Wide Substellar Companion to a Nearby Low-Mass Star
• Proper motions of field L and T dwarfs
• WISE2150-7520AB: A very low mass, wide co-moving brown dwarf system discovered through the citizen science project Backyard Worlds: Planet 9
• A revisit to agglomerates of early-type Hipparcos stars
• Discovery And Characterization of Wide Binary Systems With a Very Low Mass Component
• Discovery of wide low and very low-mass binary systems using Virtual Observatory tools
• Search for bright nearby M dwarfs with Virtual Observatory tools
• Proper motions of field L and T dwarfs -II
• Reaching the boundary between stellar kinematic groups and very wide binaries. IV. The widest Washington double star systems with rho > 1000 arcsec in Gaia DR3
• Detection and characterisation of two VLM binaries: LP 1033-31 and LP 877-72
• The Gaia Ultracool Dwarf Sample -- IV. GTC/OSIRIS optical spectra of Gaia late-M and L dwarfs